// the find
0xPolygon/bor
Official repository for the Polygon Blockchain
Bor is Polygon's fork of go-ethereum that implements their Proof-of-Stake sidechain consensus (Heimdall-coordinated validator sets, sprint-based block production). It's EVM-compatible up to the London hard fork, so anything you deploy on Ethereum mainnet will run here — but you're running on Polygon PoS, not L1. Target audience is validators running Polygon nodes or developers building tooling around the chain.
Active development with a push as recently as yesterday, and the CI pipeline is genuinely thorough — nightly race condition checks, govulncheck, CodeQL, and Kurtosis-based E2E tests are all running. The installation script is unusually good for a blockchain node: picks up the right config for validator vs. sentry vs. archive roles automatically and sets up a systemd service. The `.claude/rules/` directory with 10+ domain-specific security rule files (consensus, EVM, txpool, RPC, p2p) is a real sign that the team is taking security tooling seriously in the AI-assisted-dev era. Packaging artifacts for both mainnet and Amoy testnet are first-class, not afterthoughts.
EVM compatibility is frozen at London — no Shanghai (EIP-4895 withdrawals), no Cancun (EIP-1153, blobs) — which means you're missing several years of opcode additions that Ethereum mainnet contracts may rely on, and this gap will only grow. The fork divergence from upstream geth makes rebasing painful; the `RETESTBOR.md` file existing at root suggests re-testing the merge is a recurring enough pain to warrant documentation. Hardware requirements are steep for what is nominally a sidechain (1TB storage for mainnet sync), and there's no mention of pruning modes or fast-sync in the README. Documentation links point to `wiki.polygon.technology` which has historically had accuracy problems when the chain moves faster than the docs team.